<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <div id="app">
        <button @click='change'>点击切换</button>
        <p v-if="isShow">hello today</p>
        <P v-if="temperature>30">hot</P>
    </div>
    
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
    <script>
        var app = new Vue({
            el:'#app',
            data:{
                isShow:true,
                temperature:20
            },
            methods:{
                change(){
                    this.isShow = !this.isShow;
                    this.temperature++;
                    console.log(this.temperature)

                }
            }

        })
    </script>
</body>
</html>